Multiple conventional rechargeable batteries such as Lithium-ion or Nickel metal hydride batteries may be arranged in series or parallel to obtain any desired voltage or current. For example, a set of batteries may be arranged in parallel by sandwiching the batteries between two conductors to obtain a desired current. Many of the parallel sets may be coupled in series to obtain a desired voltage of the larger set. The larger set may be electrically coupled in series or parallel with other similarly sized sets to obtain an even higher voltage or current.
The related application describes one method of managing the electrical connections in the smaller sets of batteries, in which multiple batteries are sandwiched in parallel between two conductors. That application describes a bracket which is laid into holes in the conductor and wave soldered to the conductor. The holes are aligned over the end terminals of the batteries, and the bracket is then welded to the batteries.
However, there are problems with this approach. The welding process is time consuming and prone to failure. It is also difficult to test the connection between each battery and the conductors. Another problem with this approach is the lack of electrical protection. A single battery can internally short, due to a malfunction or damage. The short can thus make unusable the entire set of batteries to which it is connected in parallel.
In addition, a short circuit between any two of: a conductor in the smaller set or the interconnections between the smaller sets or the larger sets, can short circuit some or all of the batteries.
Because rechargeable batteries can overheat and explode when short circuited, a short circuit can be catastrophic, not only to the batteries being shorted, but to the other batteries as well, because these non-shorted batteries can be overheated to the point at which they will overheat and explode. Because batteries can overheat and explode as a result of a short circuit, a major short circuit can cause the failure of one or more of the smaller sets of batteries.
It can be desirable to ensure that any solution to this problem ensure that short circuits external to the batteries are easy to repair.
What is needed is a system and method of interconnecting batteries that can help prevent a short circuit from causing the batteries to overheat, does not require welding the batteries to a bracket, and can allow the connections between the batteries and the conductors to be tested, and can prevent the failure of any of the smaller sets of batteries in the event of a short circuit internal to each of one or more of the batteries or a short circuit external to the batteries.